# Alzheimer's Should Be Called Type III Diabetes? **URL:** \ **Category:** Great Debates\ **Created:** [September 12, 2012, 12:37pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499 "2012-09-12T12:37:51Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![charmstr](https://avatars.discourse-cdn.com/v4/letter/c/53a042/32.png) [@charmstr](https://boards.straightdope.com/u/charmstr)\ **Post date:** [September 12, 2012, 12:37pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/1 "2012-09-12T12:37:51Z")
A google search of the Dope\* didn’t come up with anything on this topic, so I thought I would toss it out there. I read an [article on the Guardian site](http://www.guardian.co.uk/commentisfree/2012/sep/10/alzheimers-junk-food-catastrophic-effect) which lead to [a cover story](http://www.newscientist.com/article/mg21528801.100-brain-diabetes-the-ultimate-food-scare.html) from two weeks ago in _New Scientist_. The thrust of both articles is that [QUOTE=the Guardian article] A large body of evidence now suggests that Alzheimer’s is primarily a metabolic disease. Some scientists have gone so far as to rename it: they call it type 3 diabetes. [/QUOTE] According to both, the evidence is starting to pile up for this theory. Which is pretty interesting and all, but what I’d like to know, particularly as a type II diabetic, is why haven’t I heard about this before? Apparently, the idea has been floating around for at least seven years, but I had to find it out reading British sites? In any case, I would be interested in everyone’s thoughts on the subject. - I’ve never used Google to search a specific site so I read through the posting on the subject, but I’ve no idea if it worked properly. ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [September 12, 2012, 4:31pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/2 "2012-09-12T16:31:34Z")
Alzheimer’s as a form of diabetes has been around as an idea for a while. But 3. No. There is also diabetes insipidus and double diabetes (a person who has both 1 and 2). [http://ezinearticles.com/?What-Are-the-Three-Types-of-Diabetes?&id=1888145](http://ezinearticles.com/?What-Are-the-Three-Types-of-Diabetes?&id=1888145) [Diabetes insipidus - Wikipedia](http://en.wikipedia.org/wiki/Diabetes_insipidis) Oh, and also gestational diabetes. So that is five distinct types already recognized, although on 1 and 2 have numbers. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [September 12, 2012, 8:54pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/3 "2012-09-12T20:54:29Z")
This seems like nothing but sloppy terminology, where “diabetes” is equated with “metabolic/diet related disorder”. Which is crap. Diabetes is a very specific set of symptoms (high blood sugar) and it’s caused by misregulation of insulin signalling (in type 2, your body becomes insensitive to insulin, and in type 1 your pancreas doesn’t produce insulin). If it turns out that Alzheimers is caused by high blood sugar or improper insulin signalling, I’d be ok with a “type 3 diabetes” label. So apparently there’s evidence that poor diet contributes to Alzheimers. OK, what’s the mechanism? Poor diet causes all sorts of problems – and only one specific disease is called “diabetes”. We don’t label diet-related cardiovascular problems as “type 4 heart diabetes”. And there are forms of Alzheimers that have absolutely nothing to do with diet or metabolism – early onset genetic forms are very well understood, and are clearly caused by mutations that make amyloid plaques form in the brain. The more common late-onset form is much less well understood, and I’d bet that there are several underlying causes. For some people, it may very well turn out that their Alzheimers is caused by dietary factors (along with a mix of other things). Once we can categorize Alzheimers by different cause, we should just name them “Alzheimers type 1”. Call it “type 3 diabetes” if and only if high blood sugar and insulin regulation cause the Alzheimers. ETA: I dug into the links a little bit, and some researchers are _hypothesizing_ that alzheimers is caused by insulin resistance in the brain. Which is reasonable, but renaming the disease is not a job for early-stage basic research. Even if it’s a really catchy way to start you talks… ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [September 12, 2012, 8:58pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/4 "2012-09-12T20:58:55Z")
> [@lazybratsche](#): > > If it turns out that Alzheimers is caused by … improper insulin signalling, I’d be ok with a “type 3 diabetes” label. I believe that’s exactly what’s being suggested. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [September 12, 2012, 9:27pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/5 "2012-09-12T21:27:01Z")
Hmm. My previous post was mostly in response to the New Scientist piece, which was a fluffy piece of crap that didn’t even mention insulin or blood sugar. The Guardian piece, in contrast, is actually a nice bit of science reporting. “We cannot yet state unequivocally that poor diet is a leading cause of Alzheimer’s disease, though we can say that the evidence is strong and growing.” I can’t argue with that. But I don’t think we yet know anywhere near enough to rename or reclassify Alzheimer’s disease. ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [September 12, 2012, 10:16pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/6 "2012-09-12T22:16:41Z")
AFAICT, [here’s the direct comments](http://www.rhodeislandhospital.org/wtn/Page.asp?PageID=WTN000249) of a/the researcher who recently used the term “Type III diabetes”: > [@](#): > > ``` > “Brain insulin resistance (diabetes) is very much like regular diabetes,” de la Monte said. “Since the underlying problems continue to be just about the same, we believe that the development of new therapies would be applicable for all types of diabetes, including Alzheimer’s disease, which we refer to as Type III diabetes.” > She continued, “This study points out that once AD is established, therapeutic efforts should target several different pathways — not just one. The reason is that a positive feedback loop gets going, making AD progress. We have to break the vicious cycle. Restoring insulin responsiveness and insulin depletion will help, but we need to reduce brain stress and repair the metabolic problems that cause the brain to produce toxins.” > Ultimately, these findings will help to expand ways to both detect and treat AD. > Growing evidence supports the concept that AD is fundamentally a metabolic syndrome that leads to abnormalities linked to brain insulin and insulin-like growth factor (IGF) resistance. **In AD, brain insulin and IGF resistance and deficiencies begin early and worsen with severity of the disease. The rationale behind the progression of the disease is that insulin-resistance dysregulates lipid metabolism and promotes ceramide accumulation, thereby increasing inflammation and lipid metabolism, causing toxic ceramides to accumulate in the brain.** The end result is increased stress that threatens the survival and function of neurons in the brain. > > ``` (bolding mine) ---
**Author:** ![Docta\_G](https://avatars.discourse-cdn.com/v4/letter/d/2bfe46/32.png) [@Docta\_G](https://boards.straightdope.com/u/Docta_G)\ **Post date:** [September 12, 2012, 10:46pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/7 "2012-09-12T22:46:55Z")
I call it, “Reaganization.” ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 13, 2012, 2:21am UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/8 "2012-09-13T02:21:52Z")
> [@Docta\_G](#): > > I call it, “Reaganization.” Don’t do it here. Cheap shots that are liable to derail the thread are not appropriate. [/Moderating] ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 13, 2012, 2:23am UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/9 "2012-09-13T02:23:22Z")
This started out as more of a General Question, although I see a bit of potential controversy. I am still leaning toward moving it to General Questions, but I will hold off to see whether a real debate breaks out. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [September 13, 2012, 9:32am UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/10 "2012-09-13T09:32:52Z")
For those interested in such things, [here is one of the key papers](http://www.jci.org/articles/view/59903) (JCI April 2012) describing the notion of a ‘insulin resistant brain state’ in Alzheimer’s. The authors do, in fact, employ the term “type 3 diabetes” (found by doing a Ctrl-F in the article looking for “type 3”). As an aside, some of you may question the very idea that the brain can exhibit insulin resistance if for no other reason than traditional teaching is that glucose metabolism in the brain is a non-insulin-dependent process. However, as demonstrated in [this work](http://diabetes.diabetesjournals.org/content/51/12/3384.full) (among others), “there is a significant element of brain glucose uptake that is insulin sensitive”. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [September 13, 2012, 6:28pm UTC](https://boards.straightdope.com/t/alzheimers-should-be-called-type-iii-diabetes/634499/11 "2012-09-13T18:28:36Z")
Intriguing. I’ll quote from that JCI 2012 paper, though: > [@](#): > > A third type of diabetes has been proposed as a neuropathogenic mechanism of AD (26–28, 32, 120). However, such a form of diabetes is not in agreement with several observations. While the defining clinical feature of both T1D and T2D is hyperglycemia (153), there is no evidence that the brain in AD is hyperglycemic. Moreover, the insulin resistance we demonstrated in AD brains occurred in the absence of T1D or T2D and did not affect glucose uptake in neurons the way peripheral insulin resistance does in muscle, fat, and liver. The term diabetes consequently seems inappropriate to describe the state of the AD brain. A more accurate term, in our view, is insulin-resistant brain state… And that study doesn’t really say whether insulin resistance causes alzheimers or vice versa. In fact, they mention that there’s a plausible mechanism for the reverse being true: Aβ oligomers inhibit the insulin receptor. Causality is particularly tricky in Alzheimers disease; we still don’t really know whether amyloid plaques are a cause or effect of the disease.